悬臂施工连续梁桥合龙设计优化及影响分析

合龙阶段的施工工序对多跨连续梁桥的内力和累计位移均有一定的影响,以一座4跨连续梁桥为例,根据合龙阶段预应力钢束张拉阶段的不同,建立该桥的两种有限元模型,根据各个施工阶段的分析结果,对比分析预应力张拉阶段对梁体内力、累计位移的影响。结果发现,预应力张拉阶段对多跨连续梁桥结构的内力影响较小,对梁体结构的累计位移影响较大,根据分析结果,对该桥的合龙工序进行了优化。建议多跨连续梁桥在进行安全设计的同时应考虑结构线形控制的难度,对合龙工序进行优化。

Optimization Design and Effect Analysis of Closure Process of Cantilever Continuous Beam Bridge

Closure process in cantilever construction has certain effects on the inner stress and cumulative displacement of continuous beam bridge. Based on a 4-span continuous beam bridge,two finite element models are established according to the tension stages of the prestressed tendons. Then a comparative analysis of the effects of closure process on the inner stress and on the cumulative displacement is conducted. The results show that the tension stage of prestressed tendon has relatively less effect on the beam's inner stress,but has great impact on the cumulative displacement. Then the closure process of the bridge is optimized based on analysis results. It is proposed that efforts be made to optimize the closure process with respect to the difficulties in lineal controlling and as well as the security to be designed.